<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1, user-scalable=no">
    <meta http-equiv="X-UA-Compatible" content="ie=edge,chrome=1">
    <meta name="author" content="邵铭">
    <title></title>
    <style>
        * {
            box-sizing: border-box;
        }




        body {
            margin: 0;
            padding: 0;
        }




        .box {
            width: 500px;
            height: 750px;
            margin: auto;
            border: 1px solid;
            background-color: #999;
        }




        ul {
            /*width: 480px;*/
            margin: 0;
            padding: 10px;
            list-style: none;
            display: flex;
            flex-wrap: wrap;
            position: relative;
            top: -370px;
        }


        .bottom {
            right: 370px;
            margin-left: 13px;
        }


        .bottom li {
            margin-right: 6px;
        }


        .top {
            position: relative;
            left: 370px;
            /*top: -370px;*/
        }



        li img {
            width: 100px;
            height: 130px;
            margin-right: 10px;
            border-radius: 10px;
        }


        .big {
            width: 350px;
            height: 350px;
            /*border: 1px solid;*/
            margin: 10px;
        }

        .big img {
            width: 350px;
            height: 450px;
            border-radius: 10px;
        }
    </style>
</head>

<body>
    <div class="box">
        <div class="big">
            <img src="./img/big_1.jpg" alt="" id="b">

        </div>
        <div class="top">
            <ul>
                <li><img src="./img/small_1.jpg" alt=""></li>
            </ul>
            <ul>
                <li><img src="./img/small_2.jpg" alt=""></li>
            </ul>

            <ul>
                <li><img src="./img/small_3.jpg" alt=""></li>
            </ul>
        </div>

        <div class="bottom">
            <ul>
                <li><img src="./img/small_4.jpg" alt=""></li>
                <li><img src="./img/small_5.jpg" alt=""></li>
                <li><img src="./img/small_6.jpg" alt=""></li>
                <li><img src="./img/small_7.jpg" alt=""></li>
                <li><img src="./img/small_8.jpg" alt=""></li>
                <li><img src="./img/small_9.jpg" alt=""></li>
                <li><img src="./img/small_10.jpg" alt=""></li>
                <li><img src="./img/small_11.jpg" alt=""></li>
            </ul>
        </div>

    </div>
</body>

</html>
<script>
    var lis = document.querySelectorAll('li');
    var b = document.getElementById('b');
    var index = 0;
    for (var i = 0; i < lis.length; i++) {
        lis[i].index = i + 1;
        lis[i].onmouseover = function () {
            b.src = "./img/big_" + this.index + ".jpg";
        }
    }

</script>